An overshot is a device used in the drilling industry to retrieve core barrels and other equipment from a downhole location. Typically, the equipment to retrieve defines a spearhead point pointing generally upwardly to which the overshot can lock.
The overshot typically includes a pair of pivotally mounted lifting dogs that can be spread apart temporarily to receive the spearhead point therebetween. For safety and efficiency reasons, there is a need for very securely maintaining the spearhead point between the lifting dogs. Many currently existing overshots do not satisfy this requirement. A related requirement is that the overshot easily binds to the spearhead point. Existing overshots sometime present a manual operation to secure attachment of the overshot the spearhead point, which can sometimes fail.
Finally, once the equipment as been retrieved, there is a need to remove the equipment from the overshot. Many currently existing overshots present the possibility of causing injuries to workers during that process, for example when the overshot and the core barrel are over the head of the operator.
Against this background, there exists a need in the industry to provide an improved overshot.
An object of the present invention is therefore to provide an improved overshot.